.top {
    background-image: url("../img/banner_qtah.jpg");
    height: 608px;
    /*width: 100%;*/
    background-size: 100% 100%;
    /*height: calc(1000 * 808px / 1920);*/
    color: white;
}

.width-1000 {
    width: 1000px;
}

.width-900 {
    width: 900px;
}

.logo {
    background-image: url("../img/logo_g0yv.jpg");
    height: 141px;
    width: 204px;
}

/* + 兄弟选择器*/
.logo + div > div:nth-child(1) {
    background-image: url("../img/icon2_03_uc2a.png");
    width: 30px;
    height: 30px;
}

.top > div:nth-child(2) {
    background-color: rgb(230, 145, 55);
    height: 50px;
}

.nav > div {
    padding: 0 20px;
    line-height: 50px;
    cursor: pointer;
}

/*鼠标移上去事件*/
.nav > div:hover {
    background-color: white;
    color: rgb(230, 145, 55);
}

/*-----------------------------广告---------------*/
.ad {
    /*height: calc(1000 * 808px / 1920 - 141px - 50px);*/
    /*display: flex;*/
    /*align-items: center;*/
    height: 420px;
}

.ad > div > div:nth-child(1) {
    font-size: 50px;
    /* 两个参数情况下：上下距离  左右距离*/
    margin: 10px 0;
}

.dian {
    margin: 0 20px;
}

.ad > div > div:nth-child(2) {
    /*默认最小字体为12px*/
    font-size: 10px;
}

.ad > div > div:nth-child(2) > div {
    line-height: 25px;
}

.ad > div > div:nth-child(3) {
    font-size: 40px;
    color: rgb(230, 145, 55);
}

/* 后代选择器*/
.ad .pw {
    font-size: 30px;
    color: white;
}

.ad .pw + div {
    margin-right: 20px;
}

.ad > div > div:nth-child(3) > div:nth-child(2) {
    text-indent: 1.5em;
}

